1. Technical Field
This invention relates generally to free-piston type internal combustion engines, compressors or pumps, and in particular, to innovations which improve the controllability and efficiency of the free-piston engine or pump and reduce the toxic emissions, the weight and the size of such engines.
2. Background Art
Although advantageous in applications where pressurized fluid is used to transmit the energy, the simple concept of free-piston internal combustion engines or pumps, transferring the chemical energy of a combustible fuel direct into mechanical energy of pressurized hydraulic fluid, is rarely utilized due to the inability to control their operating characteristics, and in particular, the top and bottom end positions of the piston, sufficiently.